Shaft straightener



Feb. D K POPE l SHAFT-STRAIGHTENER Filed Feb. 9, 1940 Feb. 2, 1943.- D, POPE SHAFT S'TRAIGHTENER 27sheets-shet 2 Filed Feb. s. 1940 Patented Feb. 2, 1943 UNITED STATES PATENT OFFICE SHAFT STRAIGHTENER Demetrius K. Pope, Gary, Ind.

Application February 9, 1940, Serial No. 318,175

1 Claim. l (Cl. 153-52) The present invention relates to improvements` in shaft straighteners, and it is adapted for use more particularly for straightening the armature shafts of electric generators and motors which become bent in service.

It has been found that the shafts of electricl generators used upon railway cars become bent on the road, from various causes, the shafts being bent however only in the portion between the hub of its driving pulley and the adjacent bearing housing. The method heretofore employed for correcting this condition usually involved removing the shaft from the armature or rotor and then straightening the shaft in a lathe, using a pinch bar as a lever. Such a method however is objectionable as it is not only slow and laborious and produces uncertain results, but the removal of the shaft from the armature, especially if done often, loosens the shaft in the armature in which it should fit tightly. Moref over, the present method of removing the shafty from an armature, unless an arbor press is available, is to pull the shaft by the pulley nut, a sleeve and washers being placed over the shaft between the nut and the adjacent end of the armature, which is slow and awkward.

The primary object of the present invention is to provide a novel machine for straightening armature shafts without the necessity of removing the shafts from the armature, it embodying means for mounting the armature and its shaft in the machine as if it were mounted in its own bearings in the generator or motor, and means for definitely measuring and indicating the eX- tent to which it is bent, in combination with means for straightening the shaft under guidance of the measuring and indicating means which also indicates when the shaft has been restored to its straight condition.

Another object of the invention is to provide means in the machine for removing the shaft from and replacing it in the armature safely and with speed and facility should such become necessary or desirable for any reason.

To these and other ends, the invention consists in certain improvements and combinations and arrangements of parts all as will be hereinafter more fully described, the features of novelty being pointed out more particularly in the claim at the end of this specification.

In the accompanying drawings:

Fig. 1 is a front elevation of a shaft straightener and press constructed in accordance with the present invention; l

Fig. 2 is a top plan viewvof Fig. 1; Y

Fig. 3 is an end elevation of the machine Vas viewed from the left in Fig. 1;

Fig. 4 is a transverse vertical section taken on the line 4 4 in Fig. 1;

Fig. 5 is a vertical longitudinal section of the right hand end of the machine shown in Fig. 1, showing the jack in position for removing the shaft from an armature; Y

Fig. 6 is an end elevation of the right hand end of the machine; y

Fig. 7 is a detail view on an enlarged scale of the measuring and indicating gauge;

Fig. 8 is a detail section taken on the line 8-8 in Fig. 1; and

Fig. 9 is a detail section, taken on the line 9 9 in Fig. 1.

Similar parts are designated by the same reference characters in the different figures.

The machine provided by the present invention may be employed generally for the straightening of shafts of machinery of various kinds and for the removal of shafts from parts in which they are tted, but the invention is particularly adapted for the straightening of the armature shafts of electric generators and motors and for the removal of such shafts from their armatures and rotors. The preferred embodiment of the invention is shown in the drawings and will be hereinafter described in detail, but it is to be understood that the invention is not restricted to the precise structure shown as equivalent constructions are contemplated and such will be included within the scope of the claim.

The machine comprises a frame composed of upright angle irons l and 2 at one end and 3 and l at the other end to form supporting legs, front and rear longitudinal plates 5 and 6 welded, riveted or otherwise rigidly secured to the angle irons, angle irons 'I and 8 extending longitudf nally at the inner sides of the plates 5 and 6 and having their vertical flanges welded, lriveted or otherwise i'lxed thereto, the other flanges of these angle irons being turned inwardly and providinga longitudinal space between them, a plate S extending transversely at one end of the frame and welded, riveted or otherwise fixed to the inturned anges of the angle irons i and 2 and reinforced by front and rear plates 5a and 6a welded to the plates 5 and 6 and the angle irons I and 2 respectively, and a transverse plate I0 at the other end of the frame welded, riveted or otherwise fixed to the ,inturned flanges of the angle irons 3 and 4. Front and rear plates il and I2 are welded, riveted or otherwise Yfixed to the outer sides of the angle irons 3 and 4, these plates forming extensions of the plates 5 and 5 at the respective end of the frame, and these plates are welded, riveted or otherwise secured to horizontal angle irons I3 and I4 the inturned horizontal anges of which are welded, riveted or otherwise secured to a floor plate I5. The plates and angle irons composing the frame are preferably of metal of sufficient strength secured together with sufficient firmness to provide a rigid frame.

A pair of lower bearing block sections I6 and I1 are mounted on the longitudinally extending angle irons 1 and 8 for supporting an armature shaft in the machine. The bearing block section I6 is xed by upward extensions I8 and I9 of the plates 5 and 6 respectively and to which they are secured rmly as by bolts I8a and ISH, but the lower bearing block section I1 is adjustable longitudinally of the frame in order to accommodate armature shafts of diierent lengths, for which purpose the horizontal inturned flanges of the angle irons 1 and 8 are slotted longitudinally as at 20 and the lower side of the bearing block section I1 is provided with bolts 2l which extend through these Vslots and serve to clamp this bearing block section in different longitudinally adjusted positions.

The bearing block sections I6 and I1 are provided with complemental upper bearing block sections 22 and 23 respectively and the lower bearing block sections are provided with threaded studs 24 and 25 respectively to receive nuts 2'5 and 21 respectively for clamping the upper bearing block sections to the lower bearing block sections. The upper and lower sections of each bearing block are provided with complemental recesses 28 to receive and clamp the halves of a split bearing bushing 29 which is bored internally to closely but revolubly fit the armature shaft to be straightened, it being understood that a number of pairs of bushings will be employed which will lit interchangeably in the bearing blocks and will be bored to ht armature shafts of various sizes.

A measuring and indicating gauge 30 is adjustably connected to the upper bearing block section 22, as by an arm 33a composed of sections pivotally connected and held in different adjusted relations by a clamping screw 39h. The gauge may be of a well known type comprising a spindle 3I and a pointer 32 connected thereto and operative by inward and outward movement of the spindle to register the extent of such movement, as in thousandths of an inch, as plus and minus respectively, upon a correspondingly graduated dial 33. The gauge is supported with its spindle in a position to bear on the bent end of the shaft or preferably on an adapter sleeve 34 which is tapered or otherwise formed to accurately fit on the end of the shaft in place of its driving pulley and to be secured thereon by the nut 35, the periphery of the adapter sleeve being perfectly cylindrical and concentric with the geometrical center of the shaft. It is to be understood that adapter sleeves having bores of diiferent sizes or shapes to fit the pulley receiving ends of different armature shafts will be employed.

In the present instance, the measuring and indicating gauge is mounted directly above the end of the shaft mounted in the machine between the bearing block sections I6 and 22, and a hydraulic jack 36 is mounted on the floor I5 so that its ram 31 will be directly below the shaftor opposite to the gauge. This jack may be of any suitable or well known type, it being preferably provided however with a base plate 3S to which it is bolted or otherwise fixed, and the base plate is provided on its underside with a threaded stud 39 arranged to project downwardly through a longitudinal slot 40 in the floor I5 so that the ram 31 of the jack may be properly located longitudinally of the shaft, a nut 4I being threaded on the stud 39 for securely clamping the jack in place beneath the shaft.

The machine is also provided with a tray 45 to engage the underside of the armature to support it when the shaft is to be removed therefrom. This tray is cylindrically concave on its upper side so that the armature will be supported thereon without danger of rolling off when its shaft is removed, and the tray is supported by a jack 45 which may be of any suitable type such as a screw jack as shown. In the present instance, the tray is carried by the vertically movable screw 41 of the jack, and this screw is operated by bevel gears 48 and 49, the latter having a shaft 59 which extends through a longitudinal slot 5I in the front plate 6 and is provided at the front of the machine with a hand wheel 52 for operating it to adjust the height of the tray 45 according to the diameter of the armature placed in the machine. The jack 46 may be supported by a yoke 53 having front and rear sides 54 and 55 provided with angle irons 56 and 51 at their upper ends which rest on the inner edges of the longitudinal angle irons 1 and 8 of the frame, so that the yoke and the jack and tray thereon may be adjusted longitudinally of the machine to conform with the center of gravity of an armature placed therein. The transverse plate 9 of the frame is provided with a vertical slot 60, and this plate i5 adapted to `receive the base plate 38 of the jack 36 when the machine is to be used to remove the shaft `from the armature, the jack 36 being then removed from the floor I5 and placed in a horizontal position at the other end of the machine, with the threaded stud 39 on its base seated in the bottom of the slot'l 6U, as shown in Fig. 5 and being secured in such position with -its -ram 31 in alinement with the armature shaft, by tightening the nut 4I on the threaded stud 39. The vertical slot 66 in the plate 9 is in alinement transversely with the bearing bushing receiving portions of the bearing blocks, and the bottom of the slot 69 is so located that when the stud 39 on the jack is seated thereon and the nut 4I is tightened the ram of the jack is automatically brought into alinement with the centers of the bearing holes in the bearing blocks and with the armature shaft supported by the bearing blocks.

The operation of the machine is as follows: If it is desired to determine whether the armature shaft is true, the lower halves of appropriate bearing bushings 29 to fit the shaft are placed in the lower bearing block sections I6 and I1, the armature is then placed in the lower bearing bushings, the upper halves of the appropriate bearing bushings are then applied to the shaft and the upper bearing block sections 22 and 23 are then placed on the bearing block sections yI6 and I1 and are tightened so that the shaft is a tight t in the bearing bushings but is rotatable therein. The bearing block section I1 of course is adjusted lengthwise of the frame to conform with the length of the armature shaft before the armature is placed in the machine. The appropriate-adapter sleeve 34 is also applied and secured to the pulley relceivng end of the armature shaft. With the armature thus mounted in the machine, it may be rotated by hand, and as the spindle 3| of the gauge bears on .the adapter sleeve 34, it will indicate whether the shaft end is true or bent.

If the shaft end is true, the Apointer 32 of the gauge will'remain stationary,A as at the zero indication on the scale 33, as the armature is revolved, but if the shaft end is out of true, the pointer 32 of the indicator will move around on the dial to an extent according to the amount the shaft is bent, and the pointer will indicate the amount the shaft is bent. If for example the pointer of the gauge reads plus .015", thus indicating that the shaft is'bent .015" when the highest side of the sleeve 34 is brought opposite to Ithe spindle of the gauge during rotation of the armature, this high side of the sleeve is appropriately marked, and the armature is then rotated through a half revolution, which will bring the marked high side ofthe sleeve 34 in the center of the ram 31 of the jack placed on the floor I5. The jack is then operated to raise its ram 31, bending the shaft end upwardly while the sleeve 34 is against the spindle 3| of the gauge, and this bending action on the shaft is applied until the gauge indicates that the shaft has reached its straight axis and is bent .010 in the opposite direction, whereupon the action of the jack on the shaft is released. If the pointer of the gauge returns to zero, this indicates that the shaft has been straightened and that the shaft has a spring-back of .010", but if, after release of the action of the jack on the shaft, the pointer of the gauge still shows a bend of .005, that indicates that the shaft has a spring-back of .015 and the jack is again operated to bend the shaft end upwardly as before until the pointer of the indicator shows .015" in the opposite direction. Upon release of .the jack, the pointer should return to zero, thus allowing for a spring-back of .015. The characteristics of different shafts vary so that varying amounts of pressure may be required to straighten them, but in any case `the gauge will indicate when the shaft has been straightened, its pointer remaining at zero while the armature is revolved with the spindle of the gauge resting on the sleeve 34.

If the machine is ,to be used as a press to re= move the shaft from an armature, the jack 36 is removed from the oor I5 and mounted on the end plate 3. Also, the bearing bushing between the bearing block sections I3 and 22 is removed, and a spacer sleeve 6I is inserted between the bearing block sections I6 and 22 and the armature, and the .tray 45 is brought into a position beneath the armature and is raised by the jack 46 into supporting engagement with the underside of the armature and to bring the armature shaft in the center of the bushing hole between the bearing block sections I6 and 22. With the armature thus mounted in the machine and supported and centered by the tray 45, the jack 36 mounted on the plate 9 with its ram 31 aligned with the adjacent end of the armature shaft, is operated, thereby pushing the armature shaft through the armature while the latter is held from movement by the spacer sleeve 6I resting against the bearing block sections I and 22 and while the bearing block sections I1 and 23 prevent deection of the shaft in any direction when force is applied by the jack. In order to replace the shaft in the armature, it is only necessary to .turn the armature around in the machine and to insert the shaft into the end from which it was removed and to force theshaft into the armature by the jack while the spacer sleeve 6I occupies its previous location.

By providing bearings. in which the armature vshaft fits tightlyv but in which it may rotate while being tested or straightened, the armature occupies a position in the machine corresponding to its actual running position in its own bearings of a generator or motor, and the readings of the gauge will accurately indicate whether the shaft is true or whether bent and if so, the amount it is bent and the radius of the shaft toward which it is bent.

The shaft straightening method provided by the present invention, employing a dial indicator which is preferably of the direct reading type as shown, not only enables the amount to which the shaft is bent and the radius toward which it is bent to be deter-mined easily and quickly, but it also enables the operator to know more denitely than heretofore the effect of force applied to the shaft to straighten it and to know how much the shaft is bent in the reverse direction while straightening it, thus substantially avoiding guesswork which is no1-I only time consuming but involves the risk of overbending the shaft to straighten it. During the straightening operation, the shaft is held by the bearings so that it cannot become displaced with respect to either the gauge or the ram of the jack or equivalent device for applying the straightening force to the shaft, so that accuracy in the reading of the gauge is insured at all times and displacement of the shaft laterally from the ram of the jack under the force of the straightening action exerted thereon is prevented.

When the bearing blocks, in association with the spacer sleeve, are employed for supporting an armature for removal of its shaft, the tray supports the armature with its shaft centered in the bearing block from which the bearing bushing is removed and supports the armature when the shaft is removed therefrom, and during removal of the shaft from the armature under the action of the jack, the bearing blocks serve as guides to prevent lateral displacement of the shaft and insure movement of the shaft in an axial direction only. These features enable a single workman to perform the shaft removing operation with facility and safety.

In constructing the machine as a combined shaft straightener and press for removing the shaft, the bearing blocks perform the dual function of rotatably supporting the shaft for testing and straightening it and of guiding the shaft while being removed, and the tray may be ernployed to assist in lowering the armature into the bearings preparatory to the shaft testing and straightening operation and lifting the armature therefrom after such testing and straightening operation as well as to center and support the armature during and after removal of the shaft therefrom and, by rotating the tray and screw of its supporting jack about a vertical axis, the operation of reversing the position of the armature in the machine for replacing its shaft will be facilitated.

I claim as my invention:

An armature shaft straightener, comprising a pair of axially spaced horizontally alined bearings adapted to receive and support the armature shaft toward its ends, with the armature of the shaft at one side of its axis to indicate the radius on which the shaft is bent, and means located opposite to said gauge and cooperable with the projecting end of the shaft at the other side of its axis for applying a straightening force to said end of the shaft While the gauge cooperates therewith.

DEMETRIOS K. POPE. 

